Shouldered coupling for shafts, &amp;c.



' UNITED STATES PATENT OFFICE.

MARY -ANN BULLOCK, OF CHICAGO, ILLINOIS, EXECUTRIX OF MILAN C. BULLOCK, DECEASED, ASSIGNOR`TO SAID MARY ANN BULLOCK.

SHOULDERED COUPLING FOR SHAFTS,I&,C.

SPECIFICATION forming part of Letters Patent N 0. 646,597, dated April 3, 1900.

Application filed April 17, 1899. Serial No. 713,260. (No model.)

To all whom it may concern.:

Be it known that I, MARY ANNBULL0CK, a citizen of thev United States, residing at Chicago, in the county of Cook and State of Illinois, am eXeoutriX of the last will and testament of MILAN C. BULLOCK, deceased, late a citizen of Illinois; that the said MILAN C. BUL- LOCK, deceased, was the inventor of certain new and useful Improvements in Shouldered Couplings for Shafts or the Like; and I, MARY ANN BULLOCK, executrix, as aforesaid, do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of referencemarked thereon, which form a part of this specification.

Thisiuvention relates to au improved coupling for the sections or lengths of drill-rod tubes used in drilling apparatus-such as is employed for prospecting, well-boring, and like purposes-the coupling being intended to facilitate the lifting or withdrawal of the drillrod from the bored hole or well.

Prior to the introduction of the diamonddrill boring the drill or couplings used consisted of outside coupling-sleeves into which the ends of adjacent drill-rod sections or tubes were inserted, such couplings forming an eX- ternal enlargement of the drill-rod and forming relatively large shoulders which were utill ized in hoisting and lowering the rods for engagement with thearms of a forked clamp to which the lifting-rope was attached. In the use of such a coupling a rod was hoisted by the engagement of the forked clamp with the uppermost coupling-sleeve until the ends of the coupling-sleeve below. it came above the top of the hole, when the operator would slip a U-shaped support or holder beneath the shoulder of such lower coupling-sleeve and then lower the rod until its weight came lon said U-shaped holder, which would hold the rod from dropping back into the hole until the forked clamp attached to the lifting-bolt could be again adj usted into engagement with the coupling. Upon the introduction vof the diamond drillv such outwardly-projecting couplings could no longer be used, as it became necessary to employ a rod that would be iush or smooth on the outside and should nearly fill the hole, so as to act as a guide to the diamond bit and prevent the rod from rattling or vibrating in the hole during its rotation. With the adoption ofsuch flush-coupled rods came the necessity for special appliances for lifting the rod, which have taken the form of hoisting-plugs or lifting-jacks and similar devices having clam ping-jaws arranged to engage wit-h the outer surfaces of the rods, the jaws of such clamps being provided with serrations or teeth to prevent the rods from slipping through such clamps. In connection with such lifting-jacks are employed safetyclamps provided with serrated jaws arranged to grasp and hold the outside surface of the rods to support the rods while the clampingjaws of the'lifting-jacks are lowered to take anew hold. For moderate depths of holes devices of the kind described work successfully; but since the development of diamond drilling has brought about the boring of holes from two thousand to six thousand feet in depth much trouble has been encountered in the use of this class of appliances, where the weight of the rods is so great that the jaws of the chucks,liftingja'cks, and safety-clamps are required to be set up so tight, in order to prevent slipping, that it is a common occurrence that the rods are crushed and'split by the lateral pressure thereon of the chuckjaws and safety-clamps.

The present invention is intended to obviate the difculties above referred to, and it embraces generally the feature of an inside coupling or one where the surface of the coupling is flush with thedrill-rod sections joined thereby, and the portion of the coupling between the ends of said sections is provided with a plurality of grooves, recesses, or depressions, forming downwardly-facing shoulders adapted for engagement with teeth or projections on the jaws of clutches or safetyclamps. By this construction rods may be easily and safely held whatever may be the length of the line of the rods and no matter how heavy the weight thereof.

The invention maybe more readily understood by reference to the accompanying drawings, in which- Figure l is a section showing the joint in the drill-rod, the same consisting of a coupling-sleeve and the adjacentends of two drillrod sections, which are joined thereto. Fig. 2 is a side view of the coupling-sleeve detached from the drill-rod sections. Fig. 3 is a t etail section showing a modified form of the recesses in said coupling-sleeve.

As shown in said drawings, A indicates the coupling-sleeve of that kind known as an inside or tlush7 coupling, and B B the ends of drill-rod sections o r tubes, which are joined by the said coupling-sleeve. The main part or body of said coupling-sleeve A is of the same external diameter as the adjacent drillrod sections, and the end portions of said coupling-sleeve are reduced iu diameter and provided with screw-threaded parts ct ct',which engage corresponding screw-threaded parts b b on the rod-sections B B. The screwthreaded connection between the said parts may be of any usual or preferred construction; but as herein shown the screw-threads have bearing-surfaces which at the sides of the threads that. take the pressure due to the weight of the supported parts are perpendiculai` to the central axis of the rod. Moreover, as shown in the drawings, the ends of the drill-rod sections are beveled or inclined and engage corresponding conical and inwardlytapering surfaces at the shoulders formed at the ends of the central or enlarged part of the coupling-sleeve.

Upon the central or thicker portion of the coupling-sleeve are formed a plurality of circumferential recesses A A', which form a plurality of downwardly-facing shoulders A2 A2. `As shown in Figs. l and 2, the lower side walls of the recesses A are made tapered or inclined to facilitate the engagement of the teeth of the clamping-jaws therewith, this construction making the outer parts of the recesses wider than their inner parts to enable said teeth to more readily enter the same for engagement with the downwardlyfacing shoulders. This particular form of recesses is not, however, essential, and they may be of a square form, like the recesses A3, which are similar to 'those separating the threads of a square-threaded screw, as seen in the modification, Fig. The couplingsleeve so provided with recesses adapted to forma plurality of holding surfaces or shoulders is made longer than usual, so as to be of suticientlength for proper engagement with the clamping devices used and to receive as manycorrugations as may be required for the proper application of a safety-clamp o1' the jaws of a lifting-jack or those of a chuck by which the rod is secured to the feed-screw of a drilling-machine adapted to give rotative and advance movement to the drill-rod.

By providing the coupling-sleeve with recesses forming a plurality of shoulders, as described, it becomes possible to effect engagement of the clamping or chuck jaws with the tube without undue pressure thereon or such pressure as is likely to crush or injure the rod, while at the same time affording a positive and safe engagement of said jaws with the drill-tube. While the coupling-sleeve illustrated is provided with recesses forming continuous circumferential grooves and this construction is preferred because greatly facilitating the formation of the shoulders, yet it will be obvious that downwardly-facing shoulders adapted to afford proper holding engagement with the teeth of clamping-jaws may be provided by recesses in the couplingsleeve having other form than continuous grooves, and it is not therefore desired that the invention should be restricted to a construction having such continuous or circumferent-ial grooves.

Vhat is claimed as the invention is l. A tubular coupling-sleeve for tubular drill-rods which is reduced in thickness at its ends to engage the adjacent ends of the drillrod sections and is provided in its central thicker part with a plurality of recesses forming downwardly-facing shoulders.

The combination with tubular drill-rod sections, of a coupling-sleeve having its ends reduced in diameterand provided with scrc\ threads to enter and engage adjacent ends of the drill-rod sections and having its central thicker part flush with the outer surface of the drill-rod sections, and provided with a plurality of recesses or grooves forming downwardly-facing shoulders.

3. The combination with tubular drill-rod sections having conically-beveled ends, of a coupling-sleeve having its ends reduced in diameter and provided with screw-threads to enter and engage adjacent ends of the drill-rod sections and having its central thicker part flush with the outer surface of the drill-rod sections; said coupling-sleeve being provided with a plurality of peripheral recesses forming downwardly-facing shoulders and oppositely-facing inwardly-inclined surfaces at the ends of the central part of the couplingsleeve adapted to engage the beveled ends of the drill-rod sections.

In testimony that I, MARY ANN BULLocK, executrix, as aforesaid, claim the foregoing as the invention of the said MILAN C. BUL- LOCK, deceased, I affix my signature, in the presence of two witnesses, this 11th day of April, A. D. 1899.

MARY ANN BULLOCK, Ecculri of Ute esta/e of lll/'lun C'. Bullock,

deceased.

Witnesses:

GRACE C. BAR'rHoLF, MARGARET F. BULLocK.

IOO

tor;

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